Quick and reliable methods for the determination of trace levels of sulfur in a wide variety of sample matrices have long been pursued by the analytical chemist. As with many nonmetallic elements, sulfur has not proven easily amenable to detection of microgram and sub-microgram quantities. This has been further complicated by the fact that techniques for separating and/or concentrating sulfur at these levels are sometimes cumbersome. The result is that, at best, methods for determining traces of sulfur usually are tedious and require considerable operator time and skill.
As a specific example, there exists a need for an improved method for routinely determining sulfur in a salt matrix in the range of 0.5 to 100 ppm. Existing titrimetric or colorimetric methods are found to be either insufficiently sensitive for this determination or excessively time consuming. Known turbidimetric and polarographic methods are also found disadvantageous due to lack of specificity and/or reproducibility. Known instrumental techniques which have been before used to determine sulfur include X-ray fluorescence, neutron activation, and charged-particle activation analysis, but these oftentimes either are not adequately sensitive or, in cases, would be impractical.
Consequently, a fast and highly sensitive method of good specificity and reproducibility, for determining total inorganic sulfur, would represent a highly desired advance in the state of the art.